FAQs: Predictions

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What is a prediction?

A good prediction will make a plausible claim about something noteworthy in the foreseeable future (up to a year out) about which reasonable people may have differing forecasts.

A prediction will consist of the following:

  • A claim about the future.
  • Acceptance criteria that will allow an independent judge to decide whether the claim turns out to be true or false.
  • And, if possible, a verification link or source that a judge can cite to justify her opinion.

If you are familiar with SMART goals, a good prediction is much like one of those, insofar as it will be specific, measurable, achievable (or plausible), relevant, and time-bound.

An acceptable prediction must be one that can be judged independently (that is, by someone other than the person making the prediction himself) based on public information.

What is a prediction claim?

A claim is an affirmative, falsiable statement that will be time-bound to a given date in the future.

Affirmative means that, for clarity, you should avoid negative or otherwise confusing statements:

# Bad: uses "not"
I predict that the Democratic candidate in this year's U.S. presidential election will not win more votes than the Republican candidate.

# Good: same claim without negation
I predict that the Republican candidate in this year's U.S. presidential election will win more votes than the Democratic candidate.

Falsifiable means that the statement can be clearly judged true or false:

# Bad: use of term "best" invites subjective disagreements and endless debate
I predict that Harvard will be the best university in the U.S. this year.

# Good: provides clear criteria for determining whether claim is true
I predict that Harvard will be the top-ranked national university in this year's US News & World Report college rankings.

The claim should also be time-bound. In scheduling the claim, you will be required to specify a judgment date as well as a deadline for making forecasts. But specifying a time constraint will make the prediction clearer and provide information necessary for both judges and forecasters.

# Bad: time is scale not clear
I predict that the president's economic plan will shrink the US economy.

# Good: clearly indicates a time range and judgment date for evaluating claim
I predict that the economic growth for the US economy as measured in GDP will be less than zero in the third quarter of this year.

What are prediction acceptance criteria?

Prediction criteria denote additional information that can be useful to forecasters in evaluating claims and judges in deciding them. You can also provide any background information you feel is relevant here.

Try to keep your prediction itself clean and precise. Use this section for the qualifiers and fine print.

You can use a limited subset of markdown syntax to format your criteria:

  • **bold text** for bold text
  • *italicized text* for italicized text
  • [links](/faqs/) for links
  • - lists for
    • lists

What is a prediction verification?

The verification field allows the maker of a prediction to suggest an authoritative source that a judge can use to make a final decision about the prediction once the judgment date has arrived.

Normally it would be a link or URL. For example, if you wanted to make a prediction about next month's rainfall in San Francisco, you might include a link to the National Weather Service page for the San Francisco region where the data could be obtained.

The field is not required in submitting a prediction. And the judge can choose to use a difference source in making her decision. Normally, however, a judge will try to defer to a verification link or source if present.

I've created, scheduled, and submitted my prediction. Now what?

After you've submitted your prediction, it will be evaluated by a site moderator. When approved, other users may start submitting forecasts for it.

When the judgment date arrives, a site arbiter (i.e. judge) will decide whether it was true or false.

What is a personal prediction?

If you tag your prediction with the personal tag, it will be treated a little differently than normal.

For one thing, you will get to judge it when its time for judgment comes up. This means no fore karma will be awards for any forecasts. But you will collect peer karma for any upvotes or downvotes your prediction receives.

Also, the prediction will not appear in any search results or be otherwise publicized on the site. However, your prediction will still be public. You can share the prediction URL with others, and anyone with the URL will be able to view the prediction.

What is the purpose of personal predictions?

Personal predictions can be made simply for fun. Or they can be published as a kind of commitment device. Something to motivate you to accomplish a desired goals by a specific date in the future.

They also allow for predictions to be made that might be impossible to objectively judge.

What should I do if my prediction is rejected?

Any rejections should include a note explaining why it was rejected. Simply edit your prediction and re-submit. It's also probably a good idea to review this page whenever your prediction is rejected.

Also look at any comments left for your prediction. These can often help you improve it.

How is a prediction different than a forecast?

A prediction is a statement about the future, as explain above.

A forecast is an estimate of the probability that a prediction is true. It is a number between 0 and 100, where 0 means you think there is no chance the prediction will be true and 100 means you think that it absolutely it will be true. See the Forecasts FAQ page for more information about predictions.

How is a prediction different than a forecast?

A prediction is a statement about the future, as explain above.

A forecast is an estimate of the probability that a prediction is true. It is a number between 0 and 100, where 0 means you think there is no chance the prediction will be true and 100 means you think that it absolutely it will be true. See the Forecasts FAQ page for more information about predictions.

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